Hospital elevator buttons are more frequently colonized with certain bacteria than some restroom surfaces.

Veronica Hackethal, Md, Medscape, Jul 11, 2014

Hospital elevator buttons are more frequently colonized with certain bacteria than some restroom surfaces, although most of the bacteria are not clinically relevant, according to a study published online July 7 in Open Medicine.

"Elevator buttons in 3 large urban hospitals were colonized with bacteria typical of skin commensal organisms," the authors write.

From November 5 to 21, 2012, the researchers swabbed 120 elevator buttons and 96 toilet surfaces on weekends and weekdays at 3 large, tertiary care hospitals in Toronto, Ontario, Canada. The researchers took swabs from 2 interior buttons on the ground floor and a randomly selected upper floor. They also took swabs from 2 exterior buttons: the "up" button on the ground floor and the "down" button on an upper floor.

From March 17 to 27, 2013, the researchers swabbed surfaces in men's restrooms near the elevators. They took swabs from the exterior and interior handles of the entry door, the privacy latch, and the toilet flusher.

Elevator buttons had a higher colonization prevalence than restroom surfaces (61% vs 43%; P = .008). No significant colonization differences were found for button location, day of the week, ground and upper floors, or panel position. The most commonly cultured organisms from elevator buttons were coagulase-negative staphylococci, followed by Streptococcus spp. Enterococcus and pseudomonas were rarely found. The researchers did not isolate Staphylococcus aureus, methicillin-resistance Staphylococcus aureus, or vancomycin-resistant enterococcus.

Coagulase-negative staphylococci were most frequently isolated from restroom surfaces, with colonization prevalence about the same across restroom surfaces.

Limitations included sample collection from a single geographic area, which could limit generalizability. Most sample collection occurred in the morning, which could have biased study results because of variations in cleaning schedules. Finally, results could be biased by elevator and restroom sample collection occurring in 2 different seasons, as nosocomial infections could vary by time of year.

"The majority of colonizing bacteria had low pathogenicity," the authors write.

They also note that bacterial colonization patterns in this study are "reassuring" and attribute them to good hospital cleaning practices and hand hygiene. The results, they mention, also suggest lower colonization prevalence for elevator buttons than found for computer keyboards and ultrasound transducers in past studies.

Because hospital elevator buttons do, however, present sources of potential pathogen transmission, the authors suggest several strategies to decrease risk. These include placing hand sanitizers inside and outside elevators, installing touchless sensor buttons, or enlarging some buttons to allow for elbow activation. Education targeted at elevator users about the importance of hand hygiene could also help.

"Ultimately, an awareness of risk might spur greater attention throughout a hospital," the authors emphasize.